Association of microRNA polymorphisms with the risk of myocardial infarction in a Chinese population.

MicroRNAs (miRNAs) are involved in the regulation of a variety of biological processes, such as inflammation. Dysregulation of miRNAs have been implicated in many human disease, including cardiovascular diseases. Polymorphisms in miRNA genes may affect the miRNA biogenesis and function, and thus cause changes in the expression of thousands of genes. The aim of this study was to examine whether miRNA polymorphisms (miR-146a rs2910164, miR-149 rs71428439, miR-196a2 rs11614913, miR-218 rs11134527, and miR-499 rs3746444) contribute to the risk for the development of myocardial infarction (MI). Five miRNA polymorphisms were genotyped in a total of 1808 subjects composed of 919 MI patients and 889 control individuals. The GG genotype of rs3746444 was found to be associated with a significantly increased risk of MI (recessive model, adjusted OR = 1.710, 95% CI: 1.058-2.763, P = 0.029). Although the CC genotype of rs2910164 significantly increased the risk of MI under dominant and additive models (P < 0.05), this difference disappeared after adjustment for age, sex, blood pressure, triglycerides, total cholesterol, HDL, LDL and diabetes. In addition, when rs3746444 and rs2910164 were evaluated together by the number of putative high-risk alleles, we found an increased risk of MI for subjects carrying 3-4 risk alleles (3-4 risk alleles vs. 0-1 risk allele, adjusted OR = 1.580, 95% CI: 1.069-2336, P = 0.022; 3-4 risk alleles vs. 0-2 risk allele, adjusted OR = 1.513, 95% CI: 1.031-2.219, P = 0.034). These findings indicate that miR-499 rs3746444 and miR-146a rs2910164 may represent novel markers of MI susceptibility.